TS: Clean up.

src/math/Box2.d.ts

@@ -23,7 +23,7 @@ export class Box2 {
 	expandByScalar( scalar: number ): Box2;
 	containsPoint( point: Vector2 ): boolean;
 	containsBox( box: Box2 ): boolean;
-	getParameter( point: Vector2 ): Vector2;
+	getParameter( point: Vector2, target: Vector2 ): Vector2;
 	intersectsBox( box: Box2 ): boolean;
 	clampPoint( point: Vector2, target: Vector2 ): Vector2;
 	distanceToPoint( point: Vector2 ): number;

src/math/Box3.d.ts

@@ -32,7 +32,7 @@ export class Box3 {
 	expandByObject( object: Object3D ): this;
 	containsPoint( point: Vector3 ): boolean;
 	containsBox( box: Box3 ): boolean;
-	getParameter( point: Vector3 ): Vector3;
+	getParameter( point: Vector3, target: Vector3 ): Vector3;
 	intersectsBox( box: Box3 ): boolean;
 	intersectsSphere( sphere: Sphere ): boolean;
 	intersectsPlane( plane: Plane ): boolean;

src/math/Vector3.d.ts

@@ -211,7 +211,7 @@ export class Vector3 implements Vector {
 	/**
 	 * Sets this vector to cross product of itself and v.
 	 */
-	cross( a: Vector3, w?: Vector3 ): this;
+	cross( a: Vector3, w: Vector3 ): this;
 
 	/**
 	 * Sets this vector to cross product of a and b.